A material handling device may be used for transporting, sorting, or storing goods of various sizes and properties. It is a desirable feature of material handling devices that the devices are stackable to protect the devices' contents. It is also desirable that the material handling devices are nestable within one another when the material handling devices are empty.
Kreeger et al. (U.S. Pat. No. 4,905,833) describes a nestable and stackable container having a rotatable stacking shelf mounted to the container side walls. The side walls each include an interior portion having a horizontal shoulder at the upper edge thereof, and an exterior portion having an inwardly-facing rounded pivot portion. Each shelf includes backward J-shaped portions that are disposed between the interior and exterior side wall portions, and pivot about the pivot portions to allow the stacking shelfs to rotate between stacking and nesting positions. The horizontal shoulders compress somewhat as the stacking shelfs rotate, to thereby provide a maximum resistance against rotation intermediate the stacking and nesting positions. When the stacking shelfs are pivoted to the stacking position, the stacking shelfs can support the bottom of a container of like construction when stacked.